Head-protecting airbag device

ABSTRACT

A head-protecting airbag device includes a case which houses an airbag in a folded-up configuration and a mounting bracket which is used to mount an inflator on a vehicle body structure. The case is mounted on a region of the airbag extending from one end of the inflator. The mounting bracket includes an insert region which fits in an assembling opening of the case. The assembling opening includes a receiving region which receives the insert region along an axial direction of the inflator and a limiting plane that is located in a periphery of the receiving region and holds the insert region from rotating in both directions in a circumferential direction of the inflator. The fitting of the insert region and assembling opening suppresses the airbag stored in the case in the folded-up configuration from rotating in a circumferential direction.

CROSS REFERENCE TO RELATED APPLICATIONS

The Present application claims priority from Japanese Patent ApplicationNo. 2016-036274 of Konaka et al., filed on Feb. 26, 2016, and JapanesePatent Application No. 2016-140584 of Konaka et al., filed on Jul. 15,2016, the entire disclosures of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a head-protecting airbag device thatincludes an airbag which is mountable on an upper periphery of a windowof a vehicle in an elongate folded-up configuration and deployable overthe window when actuated, an inflator for supplying the airbag with aninflation gas, a mounting bracket which mounts the inflator on a vehiclebody structure at the upper periphery of the window, and a casefabricated of synthetic resin and housing the airbag in the folded-upconfiguration.

2. Description of Related Art

JP2015-30367 discloses a known head-protecting airbag device in which anairbag is stored in a case in an elongate folded-up configuration so asto be mounted on the upper periphery of a window as is stored in thecase. In this airbag device, an inflator is assembled with the casepreliminarily, and this assembly is mounted on the upper periphery ofthe window.

However, this conventional airbag device has a complicated assemblingstructure between the inflator and the case in which a mounting bracketmounted on the inflator and a mounting section of the case are firstlymated, and a band is wound around the inflator, the mounting bracket andthe mounting section of the case.

Further, a folded-up body of the airbag for a head-protecting airbagdevice, which refers to a folded-up configuration of the airbag, is soelongate that a case cannot accommodate an entirety of the folded-upbody, and a region of the airbag which is not covered with the case canbe possibly mounted on the periphery of the window in a twisted state,which is not preferable. Accordingly, it has been desired to provide anew technology that prevents a torsion of the folded-up body of theairbag and facilitates an assembly of the inflator and the case.

SUMMARY OF THE INVENTION

The present invention has one of the object to provide a head-protectingairbag device that has an easy assembling structure between an inflatorand a case and is capable of suppressing a torsion of a folded-up bodyof an airbag from occurring when mounted on the upper periphery of thevehicle window.

The object of the invention will be attained by the followinghead-protecting airbag device:

The head-protecting airbag device includes an airbag that is mountableon an upper periphery of a window of a vehicle inside the vehicle insuch a folded-up configuration that is formed by bringing a lower edgeof the airbag at deployment close to an upper edge of the airbag. Theairbag is deployable over the window when fed with an inflation gas andincludes an inlet region which protrudes upward out of an upper edge ofan intermediate region in a front and rear direction of the airbag fortaking in the inflation gas. The airbag device further includes aninflator for feeding the airbag with the inflation gas, a mountingbracket that is coupled with the inflator and mounts the inflator on avehicle body structure at the upper periphery of the window, and a casethat is fabricated of synthetic resin and houses the airbag in thefolded-up configuration.

The inflator is generally cylindrical in shape and is so disposed as toextend along an axial direction of the airbag in the folded-upconfiguration. The inflator includes, at the first end in the axialdirection, a gas discharge region that is coupled with the inlet regionof the airbag and discharges the inflation gas into the airbag. Thesecond end of the inflator is located outside of the inlet region of theairbag.

The case is mounted on a region of the airbag ranging from a vicinity ofthe second end of the inflator towards a direction away from the gasdischarge region of the inflator.

The mounting bracket includes an insert region that extends towards thecase at an outside of the inflator and fits in an assembling opening ofthe case. The assembling opening of the case includes a receiving regionthat receives the insert region of the mounting bracket along an axialdirection of the inflator and a limiting plane that is located in aperiphery of the receiving region and holds the insert region fromrotating in both directions in a circumferential direction of theinflator. The fitting between the insert region and the assemblingopening suppresses the airbag stored in the case in the folded-upconfiguration from rotating in both directions in the circumferentialdirection.

With the head-protecting airbag device of the invention, the inflator,which has been coupled with the airbag in the folded-up configurationand held by the mounting bracket, and the case mounted on the airbag canbe assembled together in a simple fashion by moving the insert region ofthe mounting bracket along the axial direction of the inflator, i.e.along an axial direction of the airbag, and inserting it into theassembling opening of the case from the receiving region. This way theinflator and the case can be assembled together easily without using aband or the like which was used in a conventional head-protecting airbagdevice. Further, the fitting of the insert region into the assemblingopening is easy because the insert region has only to be moved along theaxial direction of the inflator or airbag. In the head-protecting airbagdevice of the invention, the insert region mated with the assemblingopening is held from rotating around the inflator by the limiting planeof the assembling opening, thus helps suppress the airbag in thefolded-up configuration from rotating in the circumferential direction.That is, the configuration that the insert region fits in the assemblingopening prevents the case from moving in a twisting fashion with respectto the insert region, i.e. with respect to the inflator coupled with themounting bracket. As a result, the airbag stored in the case in thefolded-up configuration will also be prevented from twisting withrespect to the inflator and a torsion in a region of the airbag locatedimmediately beneath the inflator will also be prevented.

Therefore, the head-protecting airbag device of the invention has aneasy assembling structure between the inflator and the case and iscapable of suppressing a torsion in the airbag in the folded-upconfiguration from occurring when mounted on the upper periphery of thewindow.

In the head-protecting airbag device of the invention, it is desiredthat the case includes a support region that covers an outercircumferential plane of the inflator and is configured to extendgenerally along the circumferential direction of the inflator from anend of the insert region in the circumferential direction of theinflator, when the inflator is viewed from a direction on the part ofthe second end.

With this configuration, the support region of the case is disposed toexpose the second end region of the inflator. This configuration willfacilitate the connection work to connect a connector with lead wiresfor feeding an actuating signal to the second end of the inflator, whenan airbag module, in which the inflator, the airbag and case areassembled together, is mounted on the upper periphery of the window ofthe vehicle.

If, when the inflator is viewed from the direction on the part of thesecond end, the support region is configured to extend generally alongthe circumferential direction of the inflator from both ends of theinsert region of the mounting bracket in the circumferential directionof the inflator, the support region will suppress the inflator frommoving with respect to the case in a direction orthogonal to the axis.In other words, the case will be suppressed from twisting in a clockwisedirection or a counterclockwise direction about the axis of theinflator, (i.e. twisting with respect to the inflator in both directionsin the circumferential direction of the inflator). Further, in theairbag device of the invention, the case is held from moving withrespect to the inflator at two remote positions in a directionorthogonal to the axis of the inflator, i.e., on the inflator itself andat the insert region located at a distance from the inflator. Thisconfiguration will further steadily suppress a twisting movement of thecase with respect to the inflator, thus further adequately suppress atwisting of the region of the airbag disposed immediately below theinflator.

Moreover, if the case includes an insert hole that receives a region ina vicinity of the second end of the inflator along the axial directionof the inflator, the insert region of the mounting bracket can beinserted into the assembling opening at the same time as the time thesecond end region of the inflator is inserted into the insert hole,which will further facilitate the assembling of the inflator and thecase.

Furthermore, in the above head-protecting airbag device, it is desiredthat the assembling opening is composed of a through slot for receivingthe insert region, and that the through slot is composed of a regionenclosed by a pair of rising walls each of which includes the limitingplane and a holding region which extends from a leading end of at leastone of the rising walls in such a manner as to hang over the insertregion and holds an outer surface of the insert region.

This configuration will further facilitate the mating work of the insertregion and the through slot because the insert region easily fits in thethrough slot such that the outer circumference of the insert region iscovered with the periphery of the through slot, i.e. by the limitingplanes of the rising walls and the holding region, merely by moving theinsert region along the axial direction of the inflator and inserting itinto the through slot.

In this instance, the holding region may be either configured to extendfrom the leading ends of both of the rising walls, or configured toconnect the leading ends of the rising walls.

Further alternatively, the case may include a retaining projection thatpenetrates the insert region and retains the insert region.

Another object of the invention is to provide a head-protecting airbagdevice in which an inflator and an airbag are securely coupled togetherthrough the use of a clamping member, without any special treatment onthe outer circumference of the inflator and without a fear ofdecoupling.

Such a head-protecting airbag device includes an airbag which ismountable on an upper periphery of a window of a vehicle inside thevehicle for deployment over the window, a generally cylindrical inflatorwhich includes a gas discharge region and feeds an inflation gas intothe airbag, and a mounting bracket for holding and mounting the inflatoron a vehicle body structure at the upper periphery of the window.

The airbag includes a generally tubular inlet region, and the inflatoris connected with the inlet region of the airbag.

The mounting bracket includes a retaining region which holds theinflator and a bag-connecting region which helps connect the inletregion of the airbag to the inflator.

The bag-connecting region is disposed at a region of the retainingregion in a vicinity of the gas discharge region of the inflator, andincludes:

-   -   a first fastened region which is in contact with an outer        circumference of the inflator on the inner circumferential plane        and is wound by an annular first clamping member on the outer        circumference; and    -   a protruding region which is located farther towards a discharge        direction of the inflation gas than the first fastened region        and is formed partially in a circumferential direction of the        inflator. The protruding region includes a step plane which        rises outwardly from the first fastened region.

The airbag and the inflator are clamped together at the first fastenedregion of the mounting bracket by the first clamping member wound aroundthe inlet region of the airbag with the protruding region and firstfastened region of the mounting bracket and a region of the inflator ina vicinity of the gas discharge region disposed inside the inlet region.

In the above head-protecting airbag device, the mounting bracketincludes the bag-connecting region which includes the first fastenedregion which is in contact with the outer circumference of the inflatoron the inner circumferential plane and is wound by the first clampingmember on the outer circumference, and the protruding region whichincludes the step plane that rises outwardly from the first fastenedregion. The protruding region of the mounting bracket and the region ofthe inflator in the vicinity of the gas discharge region are insertedinto the inlet region of the airbag, and clamping by the clamping memberis done in that state. In the above head-protecting airbag device, theprotruding region is disposed farther towards the discharge direction ofthe inflation gas than the first fastened region around which theclamping member is mounted. With this configuration, even in the eventthat a gas pressure of the inflation gas radially enlarges the clampingmember and its tightening force is lowered, the protruding region (moreprecisely, the step plane) will prevent the clamping member from movingtowards the discharge direction of the inflation gas and helps retainthe inlet region of the airbag between the step plane and the clampingmember. Thus decoupling of the inlet region from the inflator will beadequately prevented.

Therefore, the configuration of the above airbag device will provide asecure coupling of the inflator and the inlet region of the airbagthrough the use of a clamping member, without any special treatment onthe outer circumference of the inflator and without a fear ofdecoupling.

Further, in the above head-protecting airbag device, the protrudingregion of the mounting bracket is formed only partially in acircumferential direction of the inflator, not over an entirecircumference of the inflator. This configuration will facilitate aninserting work of the inflator together with the protruding region ofthe mounting bracket into the inlet region of the airbag, in comparisonwith an instance where the protruding region is formed over an entirecircumference of the inflator.

The protruding region for a secure coupling of the inflator and theairbag is preferably formed at the leading end of the mounting bracket.

In the above head-protecting airbag device, it is desired that theprotruding region includes an enlarging region which is radiallyoutwardly enlarged relative to the first fastened region and acircumferential wall region which extends further from the enlargingregion along an axial direction of the inflator. In the protrudingregion for preventing decoupling of the airbag from the inflator, it maybe also conceivable to bend and raise an end region of the fastenedregion outwardly. However, such a configuration is likely to cause lackof rigidity of the protruding region or worsen the work efficiency ininserting the protruding region into the airbag. Therefore, it is morepreferable that the protruding region includes the enlarging region thatis radially outwardly enlarged relative to the first fastened region andthe circumferential wall region that extends further from the enlargingregion along the axial direction of the inflator.

This way the plane of the enlarging region facing towards the firstfastened region serves as the step plane and the protruding region hasan enhanced rigidity because of the circumferential wall. Moreover,since the terminal of the protruding region faces forward along theaxial direction, not radially outwardly as in the enlarging region, theprotruding region will go smoothly into the inlet region without gettingstuck with the inlet region, and an inserting work of the protrudingregion will be facilitated in comparison with an instance where theterminal of the protruding region faces radially outwardly. If theprotruding region further includes a contracted region which is bentinward at the leading end of the circumferential wall such that the endplane of the protruding region faces towards the inflator, the workefficiency in the inserting work of the protruding region will befurther improved.

It is further desired, in the above head-protecting airbag device, thatthe mounting bracket further includes a second fastened region that isformed at an opposite side to the first fastened region in an axialdirection of the retaining region, and that the second fastened regionis clamped against the inflator by a second clamping member without theairbag disposed at an inner circumference of the second clamping member.

With the above configuration, since the first clamping member isadequately prevented from being decoupled from the mounting bracket byforming the protruding region on the mounting bracket, only one clampingmember will be sufficient to couple the airbag and inflator against themounting bracket without a fear of decoupling. In other words, there isno need of another clamp for stopping decoupling of the airbag andinflator at the first fastened region. Accordingly, with the secondfastened region where only the inflator is coupled to the mountingbracket, mounting of the airbag and the inflator on the mounting bracketcan be done with two clamping members, i.e. with the first clampingmember which clamps the airbag as well as the inflator at the firstfastened region and the second clamping member which clamps only theinflator against the mounting bracket at the second fastened region.

It is further preferable, in the above airbag device, that a sameclamping member can be used as the first clamping member and the secondclamping member, and that a length in a circumferential direction of thesecond fastened region, against which only the inflator is clamped, islonger than a length in a circumferential direction of the firstfastened region, against which the airbag and inflator are clamped.

This configuration will resolve the problem of the above head-protectingairbag device that, due to the absence of the airbag at the secondclamping member, there is a difference between the first clamping memberand the second clamping member in volume of the object of tightening,i.e. in condition for obtaining a predetermined tightening force in atightening work of the clamp, and will further contribute tocommonization of the clamping members, easy parts management andefficiency improvement in a tightening work of the clamps.

Furthermore, in the above head-protecting airbag device, the inletregion of the airbag is preferably provided, at the hem of the opening,with a thickened region which is formed by doubling a cloth memberforming the inlet region and integrating the doubled cloth member. Sucha thickened region will bump against the clamping member and prevent theairbag from being decoupled from the inflator even in the event that theairbag moves in a decoupling direction when a gas pressure of theinflation gas radially enlarges the clamping member and lowers thetightening force of the clamping member.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic front elevation of a head-protecting airbag deviceembodying the invention as viewed from a vehicle interior;

FIG. 2 is a vertical sectional view of the airbag device as mounted on avehicle, taken along line II-II of FIG. 1;

FIG. 3 is a vertical sectional view of the airbag device as mounted on avehicle, taken along line of FIG. 1;

FIG. 4 is a front elevation of a case for use in the airbag device ofFIG. 1;

FIG. 5 is a partial enlarged schematic perspective view of the case ofFIG. 4;

FIG. 6 is a partial enlarged end sectional view taken along line VI-VIof FIG. 4;

FIG. 7 is an end sectional view taken along line VII-VII of FIG. 6;

FIG. 8 is a front elevation of a mounting bracket for use in the airbagdevice of FIG. 1;

FIG. 9 is a schematic perspective view of the mounting bracket of FIG.8;

FIG. 10 shows an airbag for use in the airbag device of FIG. 1 in anunfolded and flatted state and the airbag folded-up and wrapped bywrapping members, by front views;

FIG. 11 shows a folded-up body formed by folding the airbag and the caselaid side by side, by schematic partial enlarged perspective view;

FIG. 12 depicts the case which houses the airbag and is assembled withthe inflator, by schematic partial enlarged perspective view;

FIG. 13 is a partial enlarged vertical section showing the fitting ofthe inflator and case, taken along an up and down direction;

FIG. 14 is a partial enlarged horizontal section showing the fitting ofthe inflator and case, taken along a front and rear direction;

FIG. 15 is a schematic partial enlarged perspective view showing thefitting of the inflator and case;

FIG. 16 is a schematic partial enlarged perspective view showing afitting of an inflator and a case in an alternative embodiment;

FIG. 17 is a schematic partial enlarged perspective view showing afitting of an inflator and a case in another alternative embodiment;

FIG. 18 is a schematic front elevation of a head-protecting airbagdevice according to another embodiment of the invention as viewed from avehicle interior;

FIG. 19 is a vertical sectional view of the airbag device of FIG. 18 asmounted on board, taken along line XIX-XIX;

FIG. 20 is a schematic perspective view of a mounting bracket used inthe airbag device of FIG. 18;

FIG. 21 shows a front elevation of the mounting bracket of FIG. 20 and asectional view taken along line A-A;

FIG. 22 is a sectional view taken along line B-B of FIG. 21;

FIG. 23 is a sectional view taken along line C-C of FIG. 21;

FIG. 24 is a sectional view taken along line D-D of FIG. 21;

FIG. 25 illustrates the way an airbag and an inflator are mounted on themounting bracket of FIG. 20;

FIGS. 26A and 26B illustrate the way the airbag and the mounting bracketof FIG. 20 are clamped together;

FIG. 27 shows a folded-up body formed by folding the airbag and a caselaid side by side in the another embodiment, by schematic partialenlarged perspective view;

FIG. 28 depicts the case which houses the airbag and is assembled withthe inflator in the another embodiment, by schematic partial enlargedperspective view; and

FIGS. 29A and 29B illustrate behaviors of the head-protecting airbagdevice of the another embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are described below withreference to the accompanying drawings. However, the invention is notlimited to the embodiments disclosed herein. All modifications withinthe appended claims and equivalents relative thereto are intended to beencompassed in the scope of the claims.

As shown in FIG. 1, a head-protecting airbag device M1 embodying thepresent invention is mounted on a vehicle V with two side windows W1 andW2 and a middle pillar CP disposed between the windows W1 and W2(between a front pillar FP and a rear pillar RP). An airbag 30 of thehead-protecting airbag device M1 is stored inside the upper peripheriesof the windows W1 and W2 in a folded-up configuration. In other words,the airbag device M1 is stored in a region ranging from the front pillarFP to an upper region of the rear pillar RP, via a roof-side rail RR. Asindicated with double-dotted lines in FIG. 1, the airbag 30 isconfigured to be deployed over not only the windows W1 and W2 but also apart of a middle pillar garnish 7, which covers the middle pillar CP,and a part of a rear pillar garnish 8, which covers the rear pillar RP.

As shown in FIGS. 1 to 3, the airbag device M1 includes the airbag 30,an inflator 12 for feeding the airbag 30 with an inflation gas, amounting bracket 17, a plurality of mounting brackets 26, mounting bolts24 and 27, a clamp 23, a case 50 and a case 52 for housing a folded-upbody 45 which is formed by folding up the airbag 30. As shown in FIGS. 1to 3, when the airbag device M1 is mounted on the vehicle V, the airbag30 (in the shape of the folded-up body 45), inflator 12, cases 50 and 52and mounting brackets 17 and 26 are covered by an airbag cover 10 on theinboard side. The airbag cover 10 of the illustrated embodiment iscomposed of a lower hem 5 a of a front pillar garnish 5 covering thefront pillar FP and a lower hem 6 a of a roof head liner 6 covering theroof side rail RR.

The front pillar garnish 5 and roof head liner 6 are fabricated ofsynthetic resin, similarly to the middle pillar garnish 7 and rearpillar garnish 8. The front pillar garnish 5 and roof head liner 6 aremounted on an inboard side of an inner panel 2, which is part of thevehicle body structure 1, with the aid of not-shown mounting means. Asindicated with double-dotted lines in FIG. 2, the airbag cover 10, whichis composed of the lower hems 5 a and 6 a of the front pillar garnish 5and roof head liner 6, is openable toward an interior of the vehicle soas to allow airbag emergence when pushed by the airbag 30.

As shown in FIG. 1, the inflator 12 is generally cylindrical in shapeand is so disposed as to extend along an axial direction of thefolded-up body 45. In the illustrated embodiment, as shown in FIGS. 1, 2and 12, the inflator 12 is disposed adjacent and along the folded-upbody 45 at a region above a central region in a front and rear directionof the folded-up body 45 and at a region above the window W2. Asindicated with double-dotted lines in FIG. 8, the inflator 12 includes agenerally cylindrical body 13, a gas discharge region 14 located at afirst end in an axial direction of the body 13, and a connection port 15located at a second end in an axial direction of the body 13. In theillustrated embodiment, the gas discharge region 14 is disposed at thefront end 13 a of the body 13, and has a smaller diameter than the body13. The gas discharge region 14 is provided with a plurality of gasdischarge ports (not shown) for discharging an inflation gas. Theconnection port 15 is located at the rear end 13 b of the body 13 forreceiving a not-shown connector to which lead wires for feeding anactuating signal are connected. In the illustrated embodiment, theinflator 12 is assembled with the airbag 30 with the aid of a clamp 23in such a manner that the region in a vicinity of the front end 13 a ofthe body 13 including the gas discharge region 14 is set inside alater-described inlet region 33 of the airbag 30 while the region in avicinity of the rear end 13 b of the body 13 including the connectionport 15 is located outside of the inlet region 33. The clamps 23 areused to fasten the airbag 30 and inflator 12 at the rear end 33 a of theinlet region 33, as shown in FIG. 11. The body 13 of the inflator 12includes a main region 13 e and a rear end region 13 c which is disposedtowards the connection port 15 and has a smaller diameter than the mainregion 13 e such that a step is formed between the main region 13 e andthe rear end region 13 c, as shown in FIG. 14. The inflator 12 ismounted on the inner panel 2 with the aid of the mounting bracket 17,clamps 23 and mounting bolts 24 which fasten the mounting bracket 17 tothe inner panel 2.

The mounting bracket 17 is made of sheet metal, and is disposed on anoutboard side of the inflator 12, as shown in FIG. 2. More specifically,as shown in FIGS. 8 and 9, the mounting bracket 17 includes a supportregion 18 which supports the outboard side of the inflator body 13, amounting region 22 which extends downward from the support region 18 andis mounted on the inner panel 2, and an insert region 21 extendingrearward from the rear end of the support region 18.

As shown in FIG. 8, the support region 18 is elongate generally in afront and rear direction, and is greater than the mounting region 22 indimension in a front and rear direction so as to cover a region of theinflator body 13 except the front and rear end regions. As shown in FIG.2, the support region 18 is formed to curve along an outer circumferenceof the inflator body 13 and fit the outer circumference of the inflatorbody 13 generally exactly. The support region 18 and the inflator body13 are assembled together with the clamps 23 which are mounted aroundthe main body 13 and support region 18. More specifically, a total ofthree such clamps 23 are used as indicated with double-dotted lines inFIG. 8; two of them are used at a front end region 19 of the supportregion 18 which is located farther forward than the mounting region 22,and a remaining clamp 23 is used at a rear end region 20 of the supportregion 18 which is located farther rearward than the mounting region 22.The front end region 19 of the support region 18 is a region to beinserted into the inlet region 33 of the airbag 30 together with theinflator 12. Accordingly, the two clamps 23 used at the front end region19 are located outside of the inlet region 33 of the airbag 30 to couplethe inlet region 33 and the inflator 12 as well as couple the inflator12 and the mounting bracket 17, as shown in FIG. 11. The root region (orrear region, which is disposed towards the mounting region 22) of thefront end region 19 serves as a fastened region 19 a fastened with theclamps 23 as shown in FIG. 8. As shown in FIG. 9, the leading-end region(or front region) of the front end region 19 serves as a raised region19 b which is disposed at a farther outboard position than the fastenedregion 19 a due to a step formed between the raised region 19 b and thefastened region 19 a. The raised region 19 b helps hold the clamps 23mounted around the fastened region 19 a in place. A rear end area of therear end region 20, which is located away from the mounting region 22,serves as a fastened region 20 a fastened by the clamp 23, as shown inFIG. 8. The fastened region 20 a is greater in width than other region(a front area) of the rear end region 20.

The mounting region 22 is configured to be disposed on a lower region ofa generally central region in a front and rear direction of the inflator12. As shown in FIGS. 2 and 8, the mounting region 22 is provided withtwo insert holes 22 a for receiving the bolts 24 for fastening to theinner panel 2, at two spaced positions in a front and rear direction.The mounting region 22 further includes, each at the front and rearedges, a retaining pawl 22 b protruding towards an outboard direction,i.e. towards the inner panel 2. Each of the mounting pawls 22 b isretained by a peripheral region of a not-shown retaining hole providedon the inner panel 2 for positioning the mounting bracket 17temporarily.

The insert region 21 extends rearward generally along the axialdirection of the inflator 12 (i.e. along a front and rear direction)from the rear end of the support region 18 and is inserted into alater-described through slot 69 formed on the case 52. Morespecifically, as indicated with double-dotted lines in FIG. 7, thesupport region 18 and insert region 21 are formed in an uneven fashion,thus, the insert region 21 extends rearward at a farther outboardposition than the support region 18, in such a manner as to form aclearance between the insert region 21 and an outer circumferentialplane of the inflator body 13 when the support region 18 is mounted onthe inflator 12. Further, the insert region 21 is formed to curve alongthe curvature of the outer circumferential plane of the inflator body 13(FIGS. 6 and 9), and has a smaller width in a circumferential directionof the inflator 12 than the support region 18 so as to fit in thethrough slot 69.

As shown in FIG. 14, the length in a front and rear direction of theinsert region 21 is configured such that the leading end 21 a region canbe inserted through the through slot 69 when assembled with the case 52and the leading end 21 a is disposed farther rearward than the mainregion 13 e of the inflator body 13 and farther forward than the rearend of the rear end region 13 c when the support region 18 and inflator12 are mated.

Each of the mounting brackets 26 is composed of a pair of plates ofmetal, which are applied to inboard and outboard sides of each oflater-described mounting tabs 38 of the airbag 30, as shown in FIGS. 11and 12. Mounting bolts 27 secure the mounting brackets 26, together withthe mounting tabs 38 of the airbag 30, to the inner panel 2, as shown inFIG. 1.

As indicated with double-dotted lines in FIG. 1, the airbag 30 isdesigned to unfold and inflate from a folded-up configuration when fedwith an inflation gas from the inflator 12 so as to cover the inboardsides of the windows W1, W2 and pillar garnishes 7 and 8 of the middlepillar CP and rear pillar RP. As shown in (A) of FIG. 10, the airbag 30includes a gas admitting region 31 which admits an inflation gas and isinflated in such a manner as to separate an inboard side wall 31 a froman outboard side wall 31 b, and a non-admitting region 36 which is soformed that the inboard side wall 31 a and outboard side wall 31 b areattached together and admits no inflation gas. In the illustratedembodiment, the gas admitting region 31 includes a protection region 32and an inlet region 33 while the non-admitting region 36 includes aperipheral region 37, a plurality of mounting tabs 38, panel regions 39and 40 and closed regions 41.

As shown in (A) of FIG. 10, the protection region 32 includes a frontprotection region 32 a deployable over the window W1 at a side of thefront seat and a rear protection region 32 b deployable over the windowW2 at a side of the rear seat. The inlet region 33 protrudes upward outof the upper edge of an intermediate region of the airbag 30 except thefront and rear end regions. The inlet region 33 of the illustratedembodiment is formed proximate the rear end of the front protectionregion 32 a, i.e. in a vicinity of the center in a front and reardirection of the airbag 30. The inlet region 33 is formed to protruderearward and upwardly out of the upper edge 30 a of the airbag 30, andis coupled to the inflator 12 at the rear end 33 a. When the airbag 30is fully inflated, the width in a front and direction of each of thefront protection region 32 a and rear protection region 32 b is reducedcompared to that in an uninflated state. The front protection region 32a and rear protection region 32 b are provided with closed regions 41which are formed by attaching the inboard side wall 31 a and outboardside wall 31 b together and help limit the thicknesses as inflated sothe airbag 30 is inflated into a panel shape elongated in a front andrear direction.

The peripheral region 37 of the non-admitting region 36 is so formed asto enclose the gas admitting region 31 all over except the rear end 33 aof the inlet region 33. The panel region 39 is disposed between thefront protection region 32 a and rear protection region 32 b, and has agenerally rectangular plate shape. The panel region 40 is located at thefront end of the airbag 30 and has a generally rectangular plate shape.The panel region 40 is provided, at the lower end, with a belt 40 awhich is formed into a generally band and extends forward.

The mounting tabs 38 are disposed at the upper edge 30 a of the airbag30 as fully deployed for mounting the upper edge 30 a of the airbag 30on the inner panel 2 (i.e. the vehicle body structure 1). A plurality(six, in this specific embodiment) of the mounting tabs 38 are formedalong the upper edge 30 a of the airbag 30, including those formed onthe belt 40 a of the panel region 40. As described above, the mountingtabs 38 are secured to the inner panel 2 with the aid of the mountingbrackets 26 and bolts 27.

The airbag 30 is mounted on the vehicle V in the shape of the folded-upbody 45 which are elongate in a front and rear direction, as shown in(B) of FIG. 10. The folded-up body 45 is formed by folding up the airbag30, from an unfolded and flattened state in which the inboard side wall31 a and outboard side wall 31 b overlap each other, in such a manner asto bring the lower edge 30 b close to the upper edge 30 a. As shown inFIGS. 2 and 3, the region in a vicinity of the upper edge 30 a of theairbag 30 is folded in a bellows fashion while the lower region isrolled on the outboard side wall 31 b starting from the lower edge 30 b.As shown in (B) of FIG. 10, the mounting tabs 38 and inlet region 33protrude out of the upper plane of the folded-up body 45.

The cases 50 and 52 for housing the airbag 30 in a folded-upconfiguration (i.e. folded-up body 45) are fabricated of thermoplasticelastomer. The cases 50 and 52 of the illustrated embodiment arefabricated of thermoplastic polyolefin (TPO). As shown in FIG. 1, theairbag device M1 includes the case 50 for housing a region of thefolded-up body 45 disposed in front of the inflator 12, in addition tothe case 52 disposed at the rear of the inflator 12. In thisspecification, a detailed description of the case 50 will be omitted.

The case 52 is disposed at a region of the folded-up body 45 rangingfrom a vicinity of the rear end 13 b of the inflator 12 towards adirection facing away from the gas discharge region 14 in a front andrear direction (i.e. at a region of the folded-up body 45 rangingrearward from a vicinity of the rear end 13 b of the inflator 12). Inthe illustrated embodiment, the case 52 is configured to cover a regionof the folded-up body 45 from the rear end 13 b of the inflator 12 tothe rear end of the folded-up body 45. As shown in FIGS. 4 and 5, thecase 52 includes a storage region 53 for housing the folded-up body 45and a connecting region 55 disposed at the front end for coupling withthe inflator 12.

As shown in FIG. 3, the storage region 53 is configured to cover anupper side and an outboard side of the folded-up body 45. The storageregion 53 is provided with a plurality of openings 53 a foraccommodating the mounting tabs 38 coupled with the mounting brackets26, as shown in FIGS. 5, 11 and 12.

As shown in FIG. 5, the connecting region 55 protrudes towards anoutboard direction O at the front end of the storage region 53. Morespecifically, the connecting region 55 includes a vertical wall region56 which extends towards the outboard direction O in an upward facingfashion from the front end of the storage region 53 and a cover region63 extending forward from the outer circumferential edge of the verticalwall region 56. As shown in FIGS. 5 and 7, the vertical wall region 56is disposed generally along an up and down direction and is providedwith an insert hole 57 for receiving the rear end 13 b region of theinflator body 13. The cover region 63 covers the rear end region of theinflator body 13 partially when the case 52 is assembled with theinflator 12. Specifically, the cover region 63 covers an upper side andan outboard side of the rear end region of the inflator body 13 up tothe rear end region of the main region 13 e. As shown in FIGS. 5 and 6,the cover region 63 is formed to curve generally along the outercircumferential plane of the inflator body 13, and includes a recipientregion 65 for receiving the insert region 21 of the mounting bracket 17.

As shown in FIGS. 5 and 7, the insert hole 57 is formed through thevertical wall region 56 in a front and rear direction so as to receivethe rear end region 13 c of the inflator body 13 along the axialdirection of the inflator 12 (i.e. in a front and rear direction). Asviewed from the axial direction of the inflator 12 (i.e. from the frontand rear direction), the insert hole 57 has a round shape so as toreceive the rear end region 13 c of the cylindrical inflator body 13. Inthe illustrated embodiment, a peripheral region 58 of the vertical wallregion 56, which constitutes the periphery of the insert hole 57,includes an inboard-side region 59 located at an inboard side I of therear end region 13 c and an outboard-side region 60 located at anoutboard side O of the rear end region 13 c. As shown in FIGS. 5 and 7,the inboard-side region 59 and outboard-side region 60 are formed in asplit-level fashion and located at dislocated positions in a front andrear direction. In the illustrated embodiment, the outboard-side region60 is formed at a farther forward position (i.e. towards the inflator12) than the inboard-side region 59. The peripheral region 58 (i.e. theinboard-side region 59 and outboard-side region 60) forming theperiphery of the insert hole 57 serves as a support region which coversan outer circumferential plane 13 d of the inflator 12 (specifically, ofthe rear end region 13 c of the inflator body 13). That is, in theillustrated embodiment, the outer circumferential plane 13 d of the rearend region 13 c of the inflator body 13 is covered entirely by theperipheral region 58 (i.e. the inboard-side region 59 and outboard-sideregion 60) which is formed to extend along the circumferential directionof the inflator 12 from vicinities of both ends of the insert region 21in the circumferential direction of the inflator 12 (i.e. end edges 21 band 21 c, which are shown in a parenthesis in FIG. 8), when the inflator12 is viewed from a direction on the part of the rear end 13 b of theinflator 12. In the illustrated embodiment, moreover, as shown in FIG. 7(double-dotted lines) and FIG. 14, at a stepped region formed betweenthe main region 13 e and rear end region 13 c of the inflator 12, theoutboard-side region 60 of the peripheral region 58 abuts against therear end plane of the main region 13 e of the inflator body 13 which isinserted into the insert hole 57, thus serves as a stopper to preventthe inflator 12 from being further inserted. Further, when the inflator12 is inserted into the insert hole 57 starting from the rear end 13 bof the body 13 and assembled with the case 52, the connection port 15 ofthe inflator 12 is exposed, as shown in FIG. 12.

The cover region 63 of the connecting region 55 of the case 52 includesa base region 64 and the recipient region 65 for receiving the insertregion 21 of the mounting bracket 17. The recipient region 65 isdisposed at an outboard side of the inflator 12 as mounted on thevehicle V. As shown in FIGS. 5 and 6, the recipient region 65 is aband-shaped region which is formed by raising a part of the cover region63 relative to the base region 64 and slitting along a circumferentialdirection to form a clearance between the base region 64 and recipientregion 65. Thus the recipient region 65 includes a through slot (or anassembling opening) 69 for receiving the insert region 21 and a holdingregion 66 which covers an outboard side of the insert region 21 insertedthrough the through slot 69. As shown in FIG. 6, the holding region 66is shaped to curve along the insert region 21 so as to hold and coverthe outer surface of the insert region 21 generally precisely. Theholding region 66 is continuous with the base region 64 on both of theends in the circumferential direction of the inflator 12 while forming avoid space between the holding region 66 and the base region 64, whichvoid space has an opening width wide enough to receive the insert region21, as shown in FIG. 7. That is, as shown in FIG. 6, at both of the endsof the holding region 66 in the circumferential direction of theinflator 12, there are formed a pair of rising walls 67 which connectthe holding region 66 and the base region 64. In other words, theholding region 66 connects the leading ends 67 b of the rising walls 67.A connecting region 68F and a connecting region 68R are formed in frontof and at the rear of the holding region 66. Each of the connectingregions 68F and 68R is continuous with the base region 64 and extendsalong the circumferential direction of the inflator 12, as shown inFIGS. 5, 7 and 15. In the illustrated embodiment, the rear connectingregion 68R is composed of the outboard-side region 60 of the peripheralregion 58 of the insert hole 57. The void space formed beneath theholding region 66 and above the connecting regions 68R and 68L has anopening width slightly greater than the thickness of the insert region21 of the mounting bracket 57, which opening width refers to a clearancein a direction perpendicular to the axis of the inflator 12 between theconnecting regions 68F and 68R and the holding region 66.

In the illustrated embodiment, a region of the recipient region 65enclosed by the holding region 66 and rising walls 67, i.e. the voidspace formed between the holding region 66 and the connecting regions68R and 68L, constitutes the through slot 69 for receiving the insertregion 21. As shown in FIG. 7, the through slot 69 is formed throughalong the axial direction of the inflator 12 (i.e. in a front and reardirection) for receiving the insert region 21 along the axial directionof the inflator 12 (i.e. in a front and rear direction). A gap betweenthe holding region 66 and the connecting region 68F serves as areceiving region 69 a to receive the insert region 21 along the axialdirection of the inflator 12 (i.e. along the front and rear direction).In the illustrated embodiment, the rising walls 67 form opposite ends ofthe through slot 69 in the circumferential direction of the inflator 12and regulate the insert region 21 from moving in the circumferentialdirection of the inflator 12. More specifically, the inner planes of therising walls 67 which are disposed in a periphery of the receivingregion 69 a form limiting planes 67 a which hold the insert region 21from moving in the circumferential direction of the inflator 21. In theillustrated embodiment, moreover, the connecting regions 68F and 68Rlocated in front of and at the rear of the holding region 66 aredisposed between the insert region 21 and inflator body 13.

That is, as shown in FIG. 13, when the insert region 21 is insertedthrough the through slot 69, both of the end edges 21 b and 21 c of theinsert region 21 in the circumferential direction of the inflator 12abut against the limiting planes 67 a of the rising walls 67. Therefore,if the insert region 21 of the mounting bracket 17 which has beenassembled with the inflator 12 is inserted through the through slot 69of the case 52, the limiting planes 67 a will prevent the insert region21 from rotating towards both directions in the circumferentialdirection of the inflator 12 with respect to the connecting region 55 ofthe case 52. In other words, the case 52 will be prevented from rotatingin both directions in the circumferential direction of the inflator 12(or folded-up body 45) with respect to the inflator 12, or preventedfrom twisting with respect to the inflator 12, and accordingly, thefolded-up body 45 stored in the case 52 will also be prevented fromtwisting or rotating in both directions in the circumferential directionof the inflator 12. Further, as shown in FIG. 14, the insert region 21of the illustrated embodiment is covered by the holding region 66 on theouter side in a direction perpendicular to the axis of the inflator 12(i.e. on the outer circumferential plane 21 d) and is supported by theconnecting regions 68F and 68R on the inner side in the directionperpendicular to the axis of the inflator 12 (i.e. on the innercircumferential plane 21 e). That is, when the insert region 21 is setin the through slot 69, both of the end edges 21 b and 21 c of theinsert region 21 in the circumferential direction of the inflator 12 andthe both surfaces (i.e. the outer circumferential plane 21 d and innercircumferential plane 21 e) of the insert region 21 in the directionperpendicular to the axis of the inflator 12 are held from moving byregions forming the inner circumferential plane of the through slot 69(i.e. by the rising walls 67, holding region 66 and connecting regions68F and 68R).

The folded-up body 45 is stored in the case 52 with the mounting tabs 38protruded out of the openings 53 a of the storage region 53 as shown inFIG. 12 and kept in place with the aid of the breakable wrapping member75 which is mounted around the storage region 53 at intervals, as shownin FIGS. 12 and 13.

Mounting of the head-protecting airbag device M1 on the vehicle V is nowdescribed. Firstly, the airbag 30 is folded up from a flatted state inwhich the inboard side wall 31 a and outboard side wall 31 b overlapeach other, as shown in (B) of FIG. 10. In the illustrated embodiment,the region in a vicinity of the upper edge 30 a of the airbag 30 isfolded in a bellows fashion on creases extending generally in parallelto the upper edge 30 a while the lower region is rolled on the outboardside wall 31 b starting from the lower edge 30 b. Thus the folded-upbody 45 is formed. Then the breakable wrapping members 75 are wrappedaround the folded-up body 45 at intervals for keeping the folded-upconfiguration, as shown in (B) of FIG. 10. Then the mounting brackets 26are attached to the mounting tabs 38 protruding out of the folded-upbody 45. The mounting bracket 17 is mounted on the inflator 12 and theinflator 12 is connected with the inlet region 33 of the airbag 30 withthe aid of the clamp 23, as shown in FIG. 11. Thereafter, the folded-upbody 45 is stored in the cases 50 and 52, and the wrapping members 75are wrapped around the cases 50 and 52 holding the folded-up body 45.Then the inflator 12 and the case 52 are assembled together by movingthe inflator 12 rearward along the axial direction such that the rearend region 13 c of the inflator body 13 is inserted through the inserthole 57 of the connecting region 55 of the case 52 while the insertregion 21 of the mounting bracket 17 is inserted through the throughslot 69 from the receiving region 69 a. Thus an airbag module AM1 isprovided as shown in FIG. 12.

Subsequently, the mounting brackets 17 and 26 are located atpredetermined positions on the inner panel 2 and fixed thereto with thebolts 24 and 27. Then not-shown lead wires extending from a suitablecontrol for actuating the inflator is connected to the connection port15 of the inflator 12. If then the front pillar garnish 5, the roof headliner 6 and the pillar garnishes 7 and 8 are mounted on the inner panel2, the head-protecting airbag device M1 is mounted on the vehicle V.

After the airbag device M1 is mounted on the vehicle V, when theinflator 12 is actuated in response to an actuating signal fed from thecontrol, an inflation gas is discharged from the inflator 12 and flowsinto the airbag 30, and the airbag 30 then pushes and opens the airbagcover 10 and is deployed downward and covers inboard sides of thewindows W1, W2, the middle pillar CP, and the rear pillar RP, asindicated with double-dotted lines in FIG. 1.

With the head-protecting airbag device M1 of the foregoing embodiment,the inflator 12, which has been coupled with the folded-up body 45 andheld by the mounting bracket 17, and the case 52 mounted on thefolded-up body 45 can be assembled together in a simple fashion bymoving the insert region 21 of the mounting bracket 17 along the axialdirection of the inflator 12, i.e. along the axial direction of thefolded-up body 45, and inserting it into the through slot (assemblingopening) 69 of the case 52 from the receiving region 69 a. That is, theinflator 12 and the case 52 can be assembled together easily withoutusing a band or the like which is used in a conventional head-protectingairbag device. Further, the insertion of the insert region 21 into thethrough slot 69 is easy because the insert region 21 has only to bemoved along the axial direction of the inflator 12 (or folded-up body45). In the airbag device M1, the insert region 21 mated with thethrough slot 69 is held from rotating around the inflator 12 by thelimiting planes 67 a of the through slot 69, thus helps suppress thefolded-up body 45 from rotating in the circumferential direction. Thatis, the configuration that the insert region 21 fits the through slot 69prevents the case 52 from moving in a twisting fashion with respect tothe insert region 21, i.e. with respect to the inflator 12 coupled withthe mounting bracket 17. As a result, the folded-up body 45 stored inthe case 52 will also be prevented from twisting with respect to theinflator 12, and a torsion in a region of the folded-up body 45 locatedimmediately beneath the inflator 12 will also be prevented.

Therefore, the head-protecting airbag device M1 of the foregoingembodiment has an easy assembling structure between the inflator 12 andthe case 52 and is capable of suppressing a torsion in the folded-upbody 45 from occurring when mounted on the upper peripheries of thewindows W1 and W2.

In the head-protecting airbag device M1 of the foregoing embodiment, thecase 52 includes the support region that covers the outercircumferential plane of the inflator 12. This support region isconfigured to extend generally along the circumferential direction ofthe inflator 12 from one end of the insert region 21 of the mountingbracket 17 in the circumferential direction of the inflator, when theinflator 12 is viewed from a direction on the part of the rear end 13 b.More specifically, in the illustrated embodiment, the connecting region55 of the case 52 includes the insert hole 57 for receiving the rear end13 b region of the inflator 12, and the peripheral region 58 of theinsert hole 57 constitutes the support region that extends generallyalong the circumferential direction of the inflator 12 from both ends ofthe insert region 21 in the circumferential direction of the inflator.That is, as shown in FIG. 12, the inflator 12 of the foregoingembodiment is inserted through the insert hole 57 in such a manner as toexpose the connection port 15 located at the rear end 13 b. Thisconfiguration will facilitate the connection work to connect a connectorwith not-shown lead wires for feeding an actuating signal to theconnection port 15 when the airbag module AM1, in which the inflator 12,the folded-up body 45 and cases 50 and 52 are assembled together, ismounted on the upper peripheries of the windows W1 and W2 of the vehicleV. If such an advantageous effect does not have to be considered, thecase may be formed without a support region for covering an outercircumferential plane of the inflator 12. Alternatively, the supportregion may be configured to cover a region in a vicinity of the rear end(second end) of the inflator.

In the head-protecting airbag device M1 of the foregoing embodiment,moreover, the support region of the case (i.e. the peripheral region 58of the insert hole 57) covers the outer circumferential plane of theinflator 12 all over, as shown in FIGS. 12 and 14. That is, the supportregion extends generally along the circumferential direction of theinflator 12 from both of the ends (i.e. end edges 21 b and 21 c) of theinsert region 21 in the circumferential direction of the inflator, whenthe inflator 12 is viewed from a direction on the part of the rear end13 b, thus supports the outer circumference of the inflator 12 (i.e. theouter circumference 13 d of the rear end region 13 c). Thisconfiguration will help suppress the inflator 12 from moving withrespect to the case 52 in a direction orthogonal to the axis, and inother words, suppress the case 52 from twisting in a clockwise directionor a counterclockwise direction about the axis of the inflator 12, ortwisting in both directions in the circumferential direction of theinflator 12 with respect to the inflator. Further, in the airbag deviceM1 of the foregoing embodiment, the case 52 is held from moving withrespect to the inflator 12 at two remote positions in a directionorthogonal to the axis of the inflator, i.e. on the inflator 12 itselfand at the insert region 21 located at a distance from the inflator 12.This configuration will further steadily suppress a twisting movement ofthe case 52 with respect to the inflator 12, thus further adequatelysuppress a twisting of the region of the folded-up body 45 disposedimmediately below the inflator 12. If such an advantageous effect doesnot have to be considered, the support region may be configured toextend from only one of the opposite ends of the insert region in thecircumferential direction of the inflator.

In the foregoing embodiment, especially, the insert hole 57 forreceiving the rear end 13 b region of the inflator 12 along the axialdirection of the inflator 12 is formed in the case 52 and the peripheralregion 58 of the insert hole 57 constitutes the support region. Withthis configuration, the insert region 21 of the mounting bracket 17 canbe inserted through the through slot 69 at the same time as the rear end13 b region of the inflator 12 is inserted into the insert hole 57,which will further facilitate the assembling of the inflator 12 and thecase 52.

In the airbag device M1 of the foregoing embodiment, the case 52includes the through slot (or assembling opening) 69 for receiving theinsert region 21, and the through slot 69 is composed of a regionenclosed by the rising walls 67 each of which includes the limitingplane 67 a and the holding region 66 which are so formed as to connectthe leading ends 67 b of the rising walls 67. The holding region 66 isconfigured to hold an outer surface (or an outboard side) of the insertregion 21. This configuration will further facilitate the mating work ofthe insert region 21 and the through slot (assembling opening) 69because the insert region 21 easily fits in the through slot 69 suchthat the outer circumference (the end edges 21 b and 21 c, the outercircumferential plane 21 d and inner circumferential plane 21 e) iscovered with the periphery of the through slot 69 (the rising walls 67,the holding region 66 and the connecting regions 68F and 68R) merely bymoving the insert region 21 along the axial direction of the inflator 12and inserting it into the through slot 69.

In the illustrated embodiment, more specifically, the limiting planes 67a of the through slot 69 hold the both ends of the insert region 21 inthe circumferential direction of the inflator 12 (i.e., the end edges 21b and 21 c) and the holding plane 66 and connecting regions 68F and 68Rabut against the both planes of the insert region 21 in the directionorthogonal to the axis of the inflator 12 (the outer circumferentialplane 21 d and inner circumferential plane 21 e). That is, the insertregion 21 is supported by the rising walls 67, the holding region 66 andconnecting regions 68F and 68R all over. Moreover, the outercircumferential plane 13 d of the inflator 12 is also covered by theperipheral region 58 of the insert hole 57 all over. That is, the insertregion 21, which is disposed at a distance from the inflator 12 in adirection orthogonal to the axis of the inflator 12, is held from movingin both directions in the circumferential direction of the inflator 12and held from moving in both directions in the direction orthogonal tothe axis of the inflator 12, i.e., the insert region 21 is held frommoving in four directions, when fitting in the through slot 69. Further,the inflator 12 inserted into the insert hole 57 is held from moving inthe direction orthogonal to the axis of the inflator 12. Therefore, theinsert region 21 inserted into the through slot 69 and the inflator 12itself fix the case 52 in a robust fashion and prevents a torsion in thefolded-up body 45.

An alternative embodiment of the invention is now described referring toFIG. 16. A case 52A includes an assembling opening 69A which is of aU-shaped section opening outwardly in a direction orthogonal to the axisof the inflator 12, and a retaining projection 77 which penetrates aninsert region 21A and retains the insert region 21A. More specifically,in order to receive the insert region 21A from the front along an axialdirection of the inflator 12, the assembling opening 69A opens towardsfront and rear directions and towards the direction orthogonal to theaxis of the inflator 12, and is provided with a pair of rising walls 67Awhich covers opposite sides of the insert region 21A in acircumferential direction of the inflator 12. In the assembling opening69A, as shown in FIG. 16, a region enclosed by the front end regions ofthe rising walls 67A serves as an inlet opening 69 a for receiving theinsert region 21A. The insert region 21A extends from a support region18A of a mounting bracket 17A, and is provided with a narrow recessedsection 21 f which is open at the rear end and receives the retainingprojection 77 of the case 52A. The retaining projection 77 includes, atthe leading end (i.e. at the leading end in a direction orthogonal tothe axis of the inflator 12), a pair of hooks 77 a which protrude in thecircumferential direction of the inflator 12 so as to be engageable withthe periphery of the recessed section 21 f. With this configuration, thelimiting planes 67 a of the rising walls 67A, which constitute theperiphery of the assembling opening 69A, hold the insert region 21A frommoving in both directions in the circumferential direction of theinflator 12, and the hooks 77 a of the retaining projection 77 suppressthe insert region 21A from moving in the direction orthogonal to theaxis of the inflator 12.

In the case 52 of the foregoing embodiment, the holding region 66connects the leading ends 67 b of the rising walls 67 and covers theouter side of the insert region 21 in the direction orthogonal to theaxis of the inflator 12 (i.e., the outer surface of the insert region21) all over. However, the shape of the holding section should not belimited thereby. By way of example, the holding section may beconfigured like a holding section 66B of a case 52B depicted in FIG. 17.The holding section 66B is formed to extend from the leading ends 67 bof both of the rising walls 67 in such a manner as to hang over theinsert region 21 and form a gap between the leading ends thereof, suchthat the holding section 66B covers the outer surface of the insertregion 21 partially. Further, the holding region may also be formed onlyon one of the rising walls, although not shown in the drawings.

In the head-protecting airbag devices of the foregoing embodiments, theinflator has the gas discharge region at the front end and the caseassembled with the inflator extends rearward from the rear end of theinflator. However, the invention may be applied to a head-protectingairbag device in which an inflator has a gas discharge region at therear end and a case assembled with the inflator extends forward from thefront end of the inflator.

A head-protecting airbag device M2 according to a further alternativeembodiment is now described. In the airbag device M2, the fasteningconfiguration of an inflator 12 and an airbag 30C against a mountingbracket 17C is slightly different from the foregoing embodiments. Asshown in FIGS. 18, 19, 27 and 28, the airbag device M2 has a generallysimilar configuration to the airbag device M1 described above except inthe mounting bracket 17C and airbag 30C. Therefore, detaileddescriptions of common members will be omitted, and the common memberswill be given common reference numerals.

As shown in FIGS. 20 to 24, the mounting bracket 17C has a generallysimilar structure to the mounting bracket 17 of the foregoing embodimentexcept in contour of a later-described retaining region (support region)18C. Therefore, detailed descriptions of common regions will be omitted,and the common regions will be given common reference numerals followedby “C”.

The retaining region (support region) 18C is a region to cover the outercircumference of the body 13 of the inflator 12 when coupled with theinflator 12, similarly to the support region 18 of the foregoingembodiment. The mounting bracket 17C is assembled with the inflator 12with a clamp 23C of sheet metal which is mounted around the inflatorbody 13 and the retaining region 18C. More specifically, a total of twoclamps 23C are used in this specific embodiment. As indicated bydouble-dotted lines in FIG. 21, one each of the clamps 23C is used at afront end region 19C of the retaining region 18C which is locatedfarther forward than the mounting region 22C, and at a rear end region20C of the retaining region 18C which is located farther rearward thanthe mounting region 22C. In this specific embodiment, the two clamps 23Care the same clamps, and the clamp 23C used at the front or firstfastened region 19 a will be referred to as a first clamping member23C-1, while the clamp 23C used at the rear or second fastened region 20a will be referred to as a second clamping member 23C-2.

The front end region 19C of the retaining region 18C is a region to beinserted into the inlet region 33C of the airbag 30C together with theinflator 12. Accordingly, the clamp 23C-1 used at the front end region19C is located outside of the inlet region 33C of the airbag 30C tocouple the inlet region 33C and the inflator 12 as well as couple theinflator 12 and the mounting bracket 17C, as shown in FIG. 23. Similarlyto the foregoing embodiment, a root region (or a rear region), which isdisposed towards the mounting region 22C, of the front end region 19Cserves as a first fastened region 19 a wound by the clamp 23C-1 as shownin FIG. 21. A leading end (or front end) region of the front end region19C serves as a protruding region 19 c. The first fastened region 19 aand protruding region 19 c constitute a bag-connecting region that helpsconnect the inlet region 33C of the airbag 30C and the inflator 12.

As shown in a parenthesis of FIG. 21, the protruding region 19 cincludes an enlarging region 19 ca which is disposed farther outsidethan, or more particularly, radially enlarged in comparison with, thefastened region 19 a, a circumferential wall region 19 cb which extendscontinuously from the enlarging region 19 ca along the axial directionof the inflator 12 and a contracted region 19 cc which is formed on theopposite end of the circumferential wall 19 cb to the enlarging region19 ca. The plane of the enlarging region 19 ca facing towards thefastened region 19 a forms a step plane 19 cd which rises outwardly fromthe fastened region 19 a. The step plane 19 cd helps hold the clamp23C-1 mounted around the fastened region 19 a in place.

As seen in a cross-sectional shape shown in FIG. 22, the circumferentialwall region 19 cb is shaped to the outer circumference of the inflator12 at such a radial height that a uniform gap is formed between thecircumferential wall region 19 cb and the outer circumference of theinflator 12. The circumferential wall region 19 cb is formed into apartial arc face, like a generally half-pipe shape. As seen in theparenthesis of FIG. 21, the circumferential wall region 19 cb extendsfor a predetermined length in the axial direction at the uniform radialheight. The rigidity of the protruding region 19 c is enhanced byforming the circumferential wall region 19 cb in such a manner as toextend continuously from the enlarging region 19 ca in the axialdirection of the inflator 12. The contracted region 19 cc is bentradially inward (i.e., towards the inflator) at an end in an axialdirection of the circumferential wall region 19 cb (i.e., at the leadingend of the circumferential wall region 19 cb.) If an end plane of thecircumferential wall region 19 cb is bent towards the inflator 12 thisway, the protruding region 19 cd will be inserted into the airbag 30Csmoothly without getting stuck.

In the rear end region 20C of the mounting bracket 17C, a rear end areaof the rear end region 20C located away from the mounting region 22Cserves as a second fastened region 20 a which is fastened by the clamp23C (23C-2), as shown in FIG. 21. The second fastened region 20 a isgreater in width than other region (i.e. the front area) of the rear endregion 20. Unlike in the front or first fastened region 19 a, the airbag30C is not disposed on the rear or second fastened region 20 a, and theclamp 23 is used only to clamp the inflator 12 and mounting bracket 17C,as shown in FIG. 24. That is, the condition for obtaining apredetermined tightening force in tightening a clamp in the rear(second) fastened region 20 a is different from that in the front(first) fastened region 19 a. To compensate the less volume of theobject of tightening due to absence of the airbag 30C, as shown in FIGS.23 and 24, the rear fastened region 20 a has a longer length in acircumferential direction than the front fastened region 19 a.

In the head-protecting airbag device M2, the inlet region 33C has theopening 33 b for connection with the inflator 12 in a vicinity of therear end 33 a. As shown in FIG. 26A, in the rear end 33 a, the clothmember forming the inlet region 33C is folded back outwardly, and thedoubled cloth member is integrated by thermal fusion bonding at thebonded region 33 e. Thus a thickened region 33 c is formed in theperiphery of the opening 33 b. The airbag 30C has a similarconfiguration to the airbag 30 of the foregoing embodiment except theinlet region 33C, and therefore, detailed descriptions of common regionswill be omitted.

The head-protecting airbag device M2 is mounted on a vehicle in asimilar fashion to the foregoing embodiment. Firstly, the airbag 30C isfolded up into a folded-up body 45, and the inflator 12 is connected tothe inlet region 33C of the folded-up body 45. Then the folded-up body45 is stored in the cases 50 and 52 to form an airbag module AM2.Specifically, when the inlet region 33C and inflator 12 are connected,as shown in FIG. 25, the retaining region 18C of the mounting bracket17C is disposed on the inflator body 13, and then the clamp 23C-2 isfastened around the inflator 12 (body 13) and the mounting bracket 17Cat the rear fastened region 20 a. The front end region of the inflator12 is inserted into the inlet region 33C of the airbag 30C via theopening 33 b together with the front end region 19C of the mountingbracket 17C, and the clamp 23C-1 is fastened on the outer circumferenceof the airbag 30C (inlet region 33C) at the front fastened region 19 aof the mounting bracket 17C. The order of fastening the clamps 23C-1 and23C-2 is changeable.

FIGS. 26A and 26B depict the way the airbag 30C and inflator 12 arefastened to the mounting bracket 17C at the front or first fastenedregion 19 a. The inner circumferential plane of the fastened region 19 aabuts against the outer circumference of the inflator 12, and the clamp23C (23C-2) is tightened around the inlet region 33C of the airbag 30Cdisposed on the outer circumference of the fastened region 19 a.

In the head-protecting airbag device M2, as best shown in FIGS. 26A and26B, the mounting bracket 17C includes the first fastened region 19 awhich is in contact with the outer circumference of the inflator 12 onthe inner circumferential plane and is wound by the clamp 23C-1 on theouter circumference, and the protruding region 19 c which includes thestep plane 19 cd that rises outwardly from the fastened region 19 a. Theprotruding region 19 c and fastened region 19 a of the mounting bracket17C and a region of the inflator 12 in a vicinity of the gas dischargeregion 14 are inserted into the inlet region 33C of the airbag 30C, andclamping by the clamp 23C-1 is done in that state.

As shown in FIG. 29A, in the airbag device M2, the protruding region 19Cis disposed farther towards a discharge direction of the inflation gas Gthan the fastened region 19 a around which the clamp 23C-1 is mounted.When the inflation gas G is produced, a gas pressure may enlarge theinlet region 33C of the airbag 30C as well as the clamp 23C-1, and atightening force of the clamp 23C-1 may be lowered. However, with theabove configuration, the protruding region 19 c (more precisely, thestep plane 19 cd) will prevent the clamp 23C-1 from moving towards thedischarge direction of the inflation gas G (towards the left in FIG.29A) and help retain the inlet region 33C of the airbag 30C between stepplane 19 cd and the clamp 23C-1. Therefore, decoupling of the inletregion 33C from the inflator 12 is adequately prevented. That is, theconfiguration of the airbag device M2 will provide a secure coupling ofthe inflator 12 and the inlet region 33C of the airbag 30C through theuse of the clamp 23C-1, without any special treatment on the outercircumference of the inflator 12 and without a fear of decoupling of theinflator 12 and inlet region 33C.

Moreover, in the head-protecting airbag device M2, the protruding region19 c of the mounting bracket 17C is formed only partially in thecircumferential direction of the inflator 12, not over an entirecircumference of the inflator 12. This configuration will facilitate aninserting work of the inflator 12 together with the protruding region 19c of the mounting bracket 17C into the inlet region 33C of the airbag30C, in comparison with an instance where the protruding region isformed over an entire circumference of the inflator. Moreover, since theprotruding region 19 c is formed at the leading end (or front end) ofthe mounting bracket 17C, a loss of material will be suppressed and adecoupling of the inflator 12 and inlet region 33C of the airbag 30Cwill be adequately prevented.

Furthermore, in the head-protecting airbag device M2, as shown in FIG.29B, the inlet region 33C of the airbag 30C is provided, at the hem ofthe opening 33B, with the thickened region 33 c which is formed bydoubling the cloth member forming the inlet region 33C and integratingthe doubled cloth member. Such a thickened region 33 c will bump againstthe clamp 23C-1 and prevent the airbag 30C from moving in a direction tobe decoupled from the inflator 12 even in the event that the gaspressure of the inflation gas G acts on the airbag 30C towards the leftin FIG. 296.

In the airbag device M2, furthermore, the protruding region 19 c of themounting bracket 17C includes the enlarging region 19 ca and thecircumferential wall region 19 cb that extends further from theenlarging region 19 ca along the axial direction of the inflator 12.With this configuration, the protruding region 19 c has an enhancedrigidity in comparison with an instance where a retaining step used toprevent a decoupling of the airbag from the inflator is formed merely bybending and raising an end region of the fastened region outwardly.Moreover, since the terminal of the protruding region 19 c faces forwardalong the axial direction, not radially outwardly as in the enlargingregion 19 ca, the protruding region 19 c will go smoothly into the inletregion 33C without getting stuck with the inlet region 33C, and aninserting work of the protruding region 19 c will be facilitated incomparison with an instance where the terminal is directed outwardly.Especially, the protruding region 19 c of the airbag device M2 furtherincludes the contracted region 19 cc that is bent inward at the leadingend of the circumferential wall 19 cb, where the end plane of theprotruding region 19 c faces towards the inflator 12. This configurationwill further facilitate the inserting work of the protruding region 19c.

As described above, in the head-protecting airbag device M2, the clamp23C-1 is adequately prevented from being decoupled from the mountingbracket 17C by forming the protruding region 19 c on the mountingbracket 17C, and therefore, only one clamp 23C will be sufficient toclamp the airbag 30C and inflator 12 against the mounting bracket 17Cwithout a fear of decoupling. In other words, there is no need ofanother clamp for stopping decoupling of the airbag and inflator at thefirst fastened region 19 a. Accordingly, mounting of the airbag 30C andinflator 12 on the mounting bracket 17C can be done with the two clamps(clamping members), i.e. with the first clamp 23C-1 which clamps theairbag 30C as well as the inflator 12 and the second clamp 23C-2 whichclamps only the inflator 12 against the mounting bracket 17C.

However, the absence of the airbag 30C at the second fastened region 20a causes a difference between the first clamp 23C-1 and the second clamp23C-2 in volume of the object of tightening, i.e. in condition forobtaining a predetermined tightening force in tightening work of theclamp. In the head-protecting device M2, in order to make an adjustmentin volumes of the objects of tightening including the fastened regionsand commonize the clamps, the length in the circumferential direction ofthe second fastened region 20 a of the mounting bracket 17C is longerthan the length in the circumferential direction of the first fastenedregion 19 a. This will contribute to easy parts management andefficiency improvement in tightening works of the clamps.

Although the inflators in the foregoing embodiments have the gasdischarge region at the front end, the invention can be applied to ahead-protecting airbag device whose inflator has a gas discharge regionat the rear end. Any clamping members which would be mounted around anobject of tightening and tightened for producing a radially reducingtightening force may be employed as the clamping member of theinvention.

What is claimed is:
 1. A head-protecting airbag device comprising: anairbag that is mountable on an upper periphery of a window of a vehicleinside the vehicle in such a folded-up configuration that is formed bybringing a lower edge of the airbag at deployment close to an upper edgeof the airbag, the airbag being deployable over the window when fed withan inflation gas and including an inlet region which protrudes upwardout of an upper edge of an intermediate region in a front and reardirection of the airbag for taking in the inflation gas; an inflator forfeeding the airbag with the inflation gas, the inflator being generallycylindrical in shape and is so disposed as to extend along an axialdirection of the airbag in the folded-up configuration, the inflatorincluding, at a first end in an axial direction of the inflator, a gasdischarge region that is coupled with the inlet region of the airbag anddischarges the inflation gas into the airbag, with a second end of theinflator located outside of the inlet region of the airbag; a case thatis fabricated of synthetic resin and houses the airbag in the folded-upconfiguration, the case being mounted at a region of the airbag rangingfrom a vicinity of the second end of the inflator towards a directionaway from the gas discharge region of the inflator; and a mountingbracket that is coupled with the inflator and mounts the inflator on avehicle body structure at the upper periphery of the window, themounting bracket including an insert region that extends towards thecase at an outside of the inflator and fits in an assembling opening ofthe case, wherein the assembling opening of the case includes areceiving region that receives the insert region of the mounting bracketalong an axial direction of the inflator and a limiting plane that islocated in a periphery of the receiving region and holds the insertregion from rotating in both directions in a circumferential directionof the inflator, thereby suppressing the airbag stored in the case inthe folded-up configuration from rotating in both directions in acircumferential direction of the airbag.
 2. The head-protecting airbagdevice of claim 1, wherein: the case includes a support region thatcovers an outer circumferential plane of the inflator; and when theinflator is viewed from a direction on the part of the second end, thesupport region is configured to extend generally along thecircumferential direction of the inflator from a vicinity of an end ofthe insert region of the mounting bracket in the circumferentialdirection of the inflator.
 3. The head-protecting airbag device of claim2, wherein, when the inflator is viewed from the direction on the partof the second end, the support region is configured to extend generallyalong the circumferential direction of the inflator from vicinities ofboth ends of the insert region of the mounting bracket in thecircumferential direction of the inflator.
 4. The head-protecting airbagdevice of claim 1, wherein the case includes an insert hole thatreceives a region in a vicinity of the second end of the inflator alongthe axial direction of the inflator.
 5. The head-protecting airbagdevice of claim 1, wherein: the assembling opening is composed of athrough slot for receiving the insert region; and the through slot iscomposed of a region enclosed by a pair of rising walls each of whichincludes the limiting plane and a holding region which extends from aleading end of at least one of the rising walls in such a manner as tohang over the insert region and holds an outer surface of the insertregion.
 6. The head-protecting airbag device of claim 5, wherein theholding region is configured to extend from the leading ends of both ofthe rising walls.
 7. The head-protecting airbag device of claim 5,wherein the holding region is configured to connect the leading ends ofthe rising walls.
 8. The head-protecting airbag device of claim 1,wherein the case includes a retaining projection that penetrates theinsert region and retains the insert region.